Genomic Surveillance of Monkeypox Virus, Minas Gerais, Brazil, 2022

Phylogenetic analysis of 34 monkeypox virus genome sequences isolated from patients in Minas Gerais, Brazil, revealed initial importation events in early June 2022, then community transmission within the state. All generated genomes belonged to the B.1 lineage responsible for a global mpox outbreak. These findings can inform public health measures.

H uman mpox (formerly monkeypox) is an emerging zoonotic disease caused by monkeypox virus (MPXV) (1,2). Since the 1970s, mpox outbreaks in humans have occurred sporadically, mainly in Africa (3). In early May 2022, mpox emerged worldwide, and case numbers increased substantially (4). On July 23, 2022, the World Health Organization (WHO) declared the mpox outbreak a Public Health Emergency of International Concern (5).
Genomic surveillance might be considered a fundamental approach to tracking circulating strains and investigating viral spread (6)(7)(8). By October 2022, Brazil had reported 12,378 mpox cases, and the state of Minas Gerais, located in southeast Brazil, reported a total of 838 cases through epidemiologic week 41 (9).
We selected 34 human MPXV-positive samples collected in Minas Gerais during June-September 2022 for whole-genome sequencing at the Central Laboratory of Public Health of Minas Gerais. The selected samples had cycle threshold values <30 and available epidemiologic patient data. The study was approved by the research ethics committee of the Ezequiel Dias Foundation (approval no. 62702222.6.0000.9507).
We used MAFFT version 7.310 (https://mafft. cbrc.jp) to align the 34 genomes obtained from this study with an additional 218 MPXV genomes collected from GISAID (https://www.gisaid.org) until October 3, 2022 (Appendix Table 2). We used BEAST version 1.10.4 (https://beast.community) to infer the Bayesian phylogeny. The Brazilian Ministry of Health Notifiable Diseases Information System provided weekly notified cases of MPXV infection in Minas Gerais.
Epidemiologic data revealed that the highest number (n = 112) of MPXV cases in Minas Gerais were reported during epidemiologic week 31 (Appendix Figure 1). The data also highlight that the metropolitan region of Belo Horizonte had the highest concentration (n = 608) of confirmed cases during June-September (Appendix Figure 2).
Using patients' clinical records, we found that 55.9% (19/34) were HIV-positive and 23.5% (8/34) reported active sexually transmitted infection. Among the screened samples, 33 were from male patients and 1 was from a female patient; patients were 22-46 (mean 32.5) 1 These authors contributed equally to this article.
Phylogenetic analysis of 34 monkeypox virus genome sequences isolated from patients in Minas Gerais, Brazil, revealed initial importation events in early June 2022, then community transmission within the state. All generated genomes belonged to the B.1 lineage responsible for a global mpox outbreak. These findings can inform public health measures.
Our phylogenetic reconstruction revealed that all genomes from the 2022 mpox outbreak grouped together (Figure). Most of the genomes we obtained from Minas Gerais grouped with MPXV genomes isolated from other regions of Brazil (Figure). Our phylogenetic reconstruction revealed that the first mpox case reported in Minas Gerais, isolated from a patient with a travel history to London, UK (GISAID accession no. EPI_ISL_13780332), grouped with a genome sequence from the United Kingdom (GISAID accession no. EPI_ISL_14439774).
We also sequenced a sample from the first confirmed mpox death in Brazil, which was reported in late July 2022. That sample was collected from a patient who resided in Minas Gerais and was in treatment for diffuse large B-cell lymphoma and HIV (10). The genome from that patient's sample belonged to the B.1.1 lineage, and in our phylogenetic reconstruction, it clustered with genome sequences isolated from Minas Gerais and from other states in Brazil.
Overall, our data revealed that an mpox case detected in Minas Gerais in early 2022 was related to a likely importation event, probably associated with a traveler returning from the United Kingdom, and then sustained MPXV community transmission. The first confirmed death reported in Minas Gerais was associated with a local MPXV infection described in a patient who reported several underlying conditions. These results contribute to genomic MPXV surveillance in Minas Gerais and increase the number of genome sequences from this virus available in GISAID. These findings and the available data can help future studies aiming to improve diagnostic protocols and vaccine development.

Acknowledgments
We thank all authors who have kindly deposited and shared genome data on GISAID (Appendix Table 2).

About the Author
Dr. Guimarães is a research scientist and analyst at the Ezequiel Dias Foundation. Her research interests and work include the molecular diagnosis and sequencing of SARS-CoV-2, monkeypox virus, and arboviruses, including dengue, Zika, chikungunya, and yellow fever viruses, and other pathogens of importance to public health.